But that affliction was not Mr. Cantor’s alone; it is shared by the political press. Reporters and commentators might want to pause and wipe the egg off their faces before they go on camera to cluck-cluck about how Mr. Cantor, Republican of Virginia, missed signs of the insurgency that took him out. There was a lot of that going around, and the big miss by much of the political news media demonstrates that news organizations are no less a prisoner of Washington’s tunnel vision than the people who run for office.